1. Field of the Invention
This invention relates to an improved friction member, and more particularly to a brake pad of the type used for Motor vehicles.
2. Description of the Prior Art
Friction members of a resin mold type used for motor vehicles (hereinbelow referred to merely as the friction members), are usually made of an asbestos fiber base including a phenolic resin of a cement composition (a binder agent) and some ingredients to improve frictional qualities such as the frictional coefficient and/or durability. The friction members also are contacted with a metal core (a back metal) by an adhesive agent.
The frictional members produced by the conventional method are obtained in the following process which comprises: mixing the asbestos fiber, the binder agent, and some ingredients; preforming with a metal mold at room temperature under pressure contact with the back metal, forming with a metal mold under heat and pressure; smoothing the surface and side face of the formed products to remove the over flowing materials thereform.
However the asbestos fiber is detrimental for our health. Whenever persons produce the friction members, for example in mixing or smoothing steps, a lot of a powdered asbestos is scattered in a factory.
Upon breathing the powdered asbestos, a person's health is impaired and cancer may result.
The friction members comprising steel fiber as a base material have been used recently to remove the problem of asbestos fiber.
However, the friction members comprising the steel fibers easily rust, and portions thereof will peel in the area between the friction member and the back metal.
Thus the aforementioned peeling phenomenon will generate a functional disorder of the brake system.